The Question:

What's the world's most long-living tree?

The Answer:

That title goes to the bristlecone pine in and
around California. The oldest known living specimen, "Methuselah," is
more than 4,700 years old.

It actually was younger than another known tree until 1964. In
that year, a graduate student doing research on Ice Age glaciers cut
down another bristlecone pine, "Prometheus," in Nevada. That one
turned out to have been at least 4,862 years old at the time.
Bristlecone pines in the area have since come under federal
protection, and Methuselah's location is being kept a secret, to keep
it from the ravages of vandals and tourists.